The song, “It Must Be Done” is the Who guitarist’s first original song written for a TV show. It will appear on the episode airing April 30th, titled “Yousaf,” in which, according to FX, “a new mission with international stakes has Philip calling on Annelise for assistance just as an old foe returns to D.C. with a vendetta” and “Stan makes a discovery that could put the FBI hot on the trail of Illegals.” Although the promo mostly uses footage from previous episodes and discloses little more about the coming episode, the 30-second clip reveals something of the song’s character, a tense, reggae-tinged number with lush percussion.
In an interview with Billboard, Townshend said that the song features in a scene involving “sex and murder.” He wrote the song with the show’s composer, Nathan Barr, and he explained that he tried to keep the song simple to highlight the show’s themes. “Here’s this couple whose whole life is about duty, duty without honor, duty without explanation,” he said. “There are no accolades. They’re not living a lie but doing things they find hard to do. Everybody has a part of their life that’s difficult to explain. For me it’s, ‘Why the fuck am I in the Who?'”